• Journal of Nutrition and Health
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• v.34 no.5
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• pp.541-546
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• 2001

This study examined the effect of various types of exercise on bone formation and resorption in rat. Five-week-old male Sprague-Daweley rats were randomly assigned to one of four groups with 10 animals in each; Control, Treadmill, Swimming, Resistance. The exercise regimen consisted of treadmill running at 25m/min, 1 hr per day, 5 days a week, and swimming for 1 hr per day, 5 days a week. Resistant exercise type with weight-bearing was designed to extend lower and upper extremities in order to feed the diet and water. Food intake showed no significant difference among groups but body weight gain and food efficiency were significantly increased in Control group as compared with exercise groups. Femur and tibia length and weight were higher in Control group and the density of therm tended to be higher in exercise groups than Control group, but this difference was not statistically significant. The breaking force of femur was the highest in Swimming group and tibia was the highest in Resistance group among groups, while there was no signigicant difference among the exercise groups. The calcium content of femur was significantly increased in Resistance group than the other groups. Calcium intake and urinary calcium showed no significant difference among groups, while calcium absorption and retention were significantly higher in exercise group than Control group. In conclusion, exercise training enhanced bone formation due to the positive effect on metabolism of calcium and bone which were different according to the types of exercise. (Korean J Nutrition 34(5) : 541∼546, 2001)

• Journal of Periodontal and Implant Science
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• v.30 no.2
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• pp.277-287
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• 2000

For the regeneration of osseous defect on the furcation area, autogeneous bone graft has been primarily used. But it has the limitation of donor site, additive surgical operation etc. Recently anorganic xenogenic bone graft materials of removing all organic components are commonly used for the regeneration of periodontal defects. This study was the comparison of the effect on the regeneration with two types xenografts($Bio-oss^{(R)}$ and Ca-P thin coated Bovine bone powder) on the furcation involvement in Beagle dogs. After surgically induced chronic periodontitis in bifurcation area of premolar, $Bio-oss^{(R)}$ and Ca-P BBP were grafted on the osseous defects. Tissue blocks including defects with soft tissues were harvested following a four-& eight-week healing interval and prepared for histologic analysis. The results of this study were as follows: 1. $Bio-oss^{(R)}$ group: there were significant differences among the $Bio-oss^{?}$ group at 4weeks and 8weeks, but the control group had various appearances : new bone formation, resorption of graft materials by multinuclear giant cells, connective tissue cells intervention in the bone graft sites etc. 2. Ca-P BBP group: lots of new bone formation were observed but the arrangement of periodontal ligament was not completed at 4weeks. New bone were replaced mature bone and the periodontal ligaments showed the functional arrangement at 8weeks. 3. By reason of undergrowing the epithelium within the osseous defects, new bone formation was not happened in the upper area of bifurcation in $Bio-oss^{(R)}$ group. 4. In Ca-P BBP group, epithelial undergrowth was not seen and generally showed much more new bone formation. 5. Ca-P BBP group showed the osteocyte-like cells at the inner portion of the graft materials 6. Both groups were similar to resorptive appearances of graft materials, but Ca-P BBP group had the better effects of osteoconduction.

• Journal of Periodontal and Implant Science
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• v.42 no.5
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• pp.166-172
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• 2012

Purpose: The aim of this study was to evaluate the improvement of osteogenic potential of biphasic calcium phosphate (BCP) bone substitute coated with synthetic cell-binding peptide sequences in a standardized rabbit sinus model. Methods: Standardized 6-mm diameter defects were created bilaterally on the maxillary sinus of ten male New Zealand white rabbits, receiving BCP bone substitute coated with synthetic cell binding peptide sequences on one side (experimental group) and BCP bone substitute without coating (control group) on the other side. Histologic and histomorphometric analysis of bone formation was carried out after a healing period of 4 or 8 weeks. Results: Histological analysis revealed signs of new bone formation in both experimental groups (4- and 8-week healing groups) with a statistically significant increase in bone formation in the 4-week healing group compared to the control group. However, no statistically significant difference in bone formation was found between the 8-week healing group and the control group. Conclusions: This study found that BCP bone substitute coated with synthetic cell-binding peptide sequences enhanced osteoinductive potential in a standardized rabbit sinus model and its effectiveness was greater in the 4-week healing group than in the 8-week healing group.

• International Journal of Oral Biology
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• v.40 no.3
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• pp.111-116
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• 2015

To determine the effect of diabetes on root resorption in periodontitis, we investigated odontoclast formation and root resorption in diabetic rats with periodontitis. Odontoclast formation was observed in three groups of F344 rats: Controls (C) were normal rats without diabetes or periodontitis; the periodontitis (P) group had mandibular first molars to be ligatured; the periodontitis with diabetes (PD) group was intravenously administered streptozotocin (50 mg/kg) to induce diabetes and had mandibular first molars to be ligatured. On days 3, 10, and 20 after ligature, tumor necrosis factor (TNF)-${\alpha}$ and receptor activator of nuclear factor-${\kappa}B$ ligand (RANKL) expression, odontoclast formation, and root resorption areas were evaluated by immunohistochemistry, tartrate-resistant acid phosphatase staining, and hematoxylin and eosin staining, respectively. The PD group showed frequent urination, weight loss, and hyperglycemia. Numbers of TNF-${\alpha}$- and RANKL-positive cells were higher in the P and PD groups than in the C group. It was more prevalent in PD group on day 3. Odontoclast formation was greater in the P and PD groups than in the C group on days 3 and 10, then decreased to same level as the C group by day 20. Root resorption in the PD and P groups showed increases on days 3 and 10, respectively, compared to the C group. These results suggest that diabetes may transiently increase root resorption on day 3 with high expression of TNF-${\alpha}$ and RANKL after periodontitis induction. This study could aid the understanding of root resorption in diabetic patients with periodontitis.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.13 no.3
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• pp.252-264
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• 1991

The purpose of this study was to compare the response of adjacent tissue and new bone formation after implantation by different methods of subperiosteal using using Proplast I and II in rabbit mandible. Microstructure of Proplast I and II was observed by scanning electron microscope. And the implantation procedure was carried out by dividing into tow groups, A and B. a group consisted of subperiosteal graft on the cortex, and the other B group was made up onlay graft following artificial decortication in the madibular body of rabbit. The experimental animals were sacrificed on the 1st, 2nd, 4th and 8th week after grafting for macroscopic and histopathologic examination. The samples extracted at the 6th postgrafting week were also used for biometric test. The result ere as follows : 1. By scanning electron microscopic observation, pore size was $50{\sim}180{\mu}m$ in the Proplast I and $100{\sim}220{\mu}m$ in Proplast II. 2. Macroscopically, infection of the graft site, deformation and displacement of the implanted materials were not observed in all experimental groups. 3. In the tissue response, infiltration of inflammatory cells and multinucleated giant cells were observed from the 2nd to the 8th week in Proplast I. Inflammatory cells decreased in number from the 2nd week in Proplast II suggesting that Proplast II is better than Proplast I. 4. Bone formation was not observed until the 8th week in the group A, but new bone formation from the surrounding graft bed and the periostium was appeared from the 4th week in the group B. 5. The maximum mean values of shear stress mere serially $65.5gf/mm^2$ in Proplast II of group B, $32.9gf/mm^2$ in Proplast I of group B, $17.0gf/mm^2$ in Proplast II of group A, and $15.7gf/mm^2$ in Proplast I. of group A.

• Journal of the Korean Society of Radiology
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• v.16 no.5
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• pp.559-565
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• 2022

In this study, we intend to develop a granulation tissue formation model. As a pilot experiment, a contrast agent was injected into the pylorus in 3 rats, the normal pylorus lumen size was confirmed, and a stent was placed. Stent migration was confirmed in to the duodenum within 1 week. In this experiment, stent was sutured and fixed to induce granulation tissue formation after gastrostomy under a fluoroscopic guidance. Twenty rats were divided into Healthy Group / Gastrostomy Group. After anesthesia of the Gastrostomy Group, an abdominal incision was performed, and gastrostomy was performed under a fluoroscopic guidance, and a stent was placed into the pylorus. In order to prevent stent migration due to peristalsis, suture between the pylorus and the proximal end of the stent was performed. Postoperative behavior and weight changes were monitored daily. Four weeks after surgery, gastrointestinal fluoroscopy imaging was performed and rats were sacrifices. To evaluate the degree of granulation formation, the stent was sectioned transversely. Gastrostomy group was statistically significantly higher than Healthy Group in granulation area ratio (all p<.001). In conclusion, it is considered that the level of tissue overgrowth formation for preclinical evaluation of the pylorus stricture model through gastrostomy is appropriate as a research evaluation tool.

• The Journal of Advanced Prosthodontics
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• v.10 no.3
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• pp.167-176
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• 2018

PURPOSE. The purpose of this study was to compare the new bone formation capability of zirconia with those of other synthetic bone grafts. MATERIALS AND METHODS. Twelve rabbits were used and four 6-mm diameter transcortical defects were formed on each calvaria. Each defect was filled with Osteon II (Os), Tigran PTG (Ti), and zirconia (Zi) bone grafts. For the control group, the defects were left unfilled. The rabbits were sacrificed at 2, 4, and 8 weeks. Specimens were analyzed through micro computed tomography (CT) and histomorphometric analysis. RESULTS. The Ti and Zi groups showed significant differences in the amount of newly formed bone between 2 and 4 weeks and between 2 and 8 weeks (P<.05). The measurements of total bone using micro CT showed significant differences between the Os and Ti groups and between the Os and Zi groups at 2 and 8 weeks (P<.05). Comparing by week in each group, the Ti group showed a significant difference between 4 and 8 weeks. Histomorphometric analysis also showed significant differences in new bone formation between the control group and the experimental groups at 2, 4, and 8 weeks (P<.05). In the comparison of newly formed bone, significant differences were observed between 2 and 4 weeks and between 2 and 8 weeks (P<.05) in all groups. CONCLUSION. Zirconia bone graft material showed satisfactory results in new bone formation and zirconia could be used as a new synthetic bone graft material.

• International Journal of Aeronautical and Space Sciences
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• v.4 no.2
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• pp.1-8
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• 2003

Satellite formation flying is the placing micro-satellites with the same mission into nearby orbits to form a cluster. Clohessy-Wiltshire equations are used to describe the relative motion and control strategies between satellites within a cluster, which are known as Hill's equations. Even though Hill's equations are powerful in determining initial conditions for the satellite formation flying, they can not accurately express the relative motion under J2 perturbation. Some methods have been developed for the determination of initial conditions to avoid limits of Hill's equation. This paper gives a new method of determining initial conditions using mean elements. For this research mean elements were transformed to osculating elements using Brouwer's theory and the orbit was propaeated with the consideration of J2-J8 to get a relative position. The results show that satellites within a cluster are maintained in the desired boundary for long period and the method is effective on a fuel saving for satellite formation flying.

• Archives of Plastic Surgery
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• v.38 no.3
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• pp.241-244
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• 2011

Purpose: Seroma formation is still major complication of abdominal donor site after TRAM flap surgery in spite of various efforts to reduce seroma formation such as closed suction drain. We performed a clinical study, that quilting suture at abdominal donor site can prevent seroma formation. Methods: Between May 2002 and September 2008, we performed 600 breast reconstructions using a unilateral TRAM flap except patients who has smoking history or abdominal scar. We performed 300 breast reconstructions without quilting sutures (A: Experimental group) until January 06, and after then 300 reconstructions with quilting sutures (B: Control group). We compared total drain output (mL), time to drain removal (days), and donor site complications between two groups. Results: There were no statistical difference at BMI (p=0.28) and time to remove suction drain between two group. (A: 8.37, B: 9.69) (p=0.40) But, total drain output was reduced with quilting suture. (A: 432.5, B: 495.2) (p=0.005) And also complication rate was decreased, such as seroma formation, epigastric bulging. (A: 1%, B: 7%) (p=0.005) Conclusion: Quilting suture is a simple and reliable method to reduce seroma formation and abdominal donor site complication.

• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.55.2-55.2
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• 2013

We examine the effect of environment on star formation activity of a sample of a galaxy group catalogue constructed from the Sloan Digital Sky Survey(SDSS DR8) given in Tempel et al.(2012). As an environmental parameter, we use the richness of the galaxy group. According to this parameter, we select 6846 galaxies in dense environment and 297335 galaxies in low environment. By comparing the two samples, we identify the different relationship between star formation rate and stellar mass. In order to compare galaxies in different environment, we fixed other parameters(color, apparent magnitude), which can affect star formation efficiency except for stellar mass. Also, based on HI mass from the ALFALFA survey, we study the environmental dependence of Kennicutt-Schmidt law which show the correlation between star formation rate and gas content.